The present invention relates to telecommunications networks and more particularly to access to data for use in such networks.
As the public switched telephone network (PSTN) becomes more sophisticated and customers demand more advanced services from the PSTN operators the amount of information which must be stored by the network operator to enable calls to be processed rises significantly.
Unless all data is stored centrally in the PSTN, access to the data from different switches in the network may become complex and ensuring that replicated data is compatible (i.e. that corresponding data is stored at all points in the network) can be difficult. Further, huge data stores may be required to store the data whether on a distributed or central basis. Access to larger data stores especially if centralised may be time consuming and when large numbers of accesses occur simultaneously blocking of the data store access network may occur.
A still further problem arises when customers wish to update service information, since either operator intervention will be required or some form of customer direct access to the network data must be permitted. Maintaining the security of network data when customer modification of the data is permitted can add to the complexities of operating such systems. Further, if the data is stored in more than one place then each time a customer wishes to update data, even on a short term basis, several data modifying messages may need to be transferred across the network.
According to the present invention there is provided a switching network having a plurality of switches interconnected to provide telecommunications services to customers, the network being responsive to signals from a first customer indicating a request for connection to a second customer wherein the network uses digital information characterising the signals received to effect connection to customer premises equipment by way of a signalling path, forwarding signals to cause the customer premises equipment to respond with data characterising the destination, the network causing a voice path to be set up between the first customer and the destination characterised by the data received.
Preferably signalling characterising the second customer connection point is transferred across the network from a first of the plurality of switches closer to the first customer to a second of the plurality of switches closer to the second customer using a first network protocol and signalling characterising the data received from the second customer is transferred from the second switch to the first switch using the same protocol.
Signalling between the second switch and the customer premises equipment may use a data channel of an ISDN connection or may use an out of band carrier arrangement on a normal telephony connection to the customer premises. Alternatively, the network may be arranged to set up a no-ring call to the second customer""s customer premises equipment for the purposes of collecting data. Ringing or no ring calls to a dedicated customer line could also be used as an alternative connection arrangement.
The data returned by the customer premises equipment may cause the network to connect the first customer to apparatus for receiving additional information from the first customer and, on receipt of such additional information, the network making a further enquiry call to the second customer, the customer premises equipment responding to the second enquiry call with data characterising a network destination.
Data forwarded to the second customer may include data defining the origin of the call whereby the customer premises equipment may return a different destination in respect of calls originating from differing locations.